Oscillator circuits are used in a variety of applications. For example, an oscillator circuit may be part of a phase locked loop (PLL). PLLs may be used, e.g., for frequency modulation radio devices or mobile communication devices. In mobile communication devices, such as mobile phones or the like, a PLL may be used for modulation, demodulation, clock recovery, and/or radio frequency synthesis. These and other applications benefit from a good linearity of the oscillator circuit, i.e. a good linearity of an oscillator characteristic relating values of an input signal applied to a frequency control input of the oscillator circuit to values of the frequency of the oscillator signal produced by the oscillator circuit.
In practice, the oscillator characteristic is determined by the implementation of the oscillator circuit and will typically show certain nonlinearities. Accordingly, there is a need for sufficient techniques which allow for estimating and/or compensating these nonlinearities.